 I'm not sure about that theory. There's no way to test it, but people do believe it. Overall, it's remarkable the progress we've made. However you slice it, at least in terms of people's ability to live longer lives, have the food they need to eat, to have shelter. We haven't solved all the problems, of course. And in many instances, the political dysfunction frustrating our attempts to do so is agonizing. But perspective still matters. It's hard to build a mostly stable, mostly prosperous civilization.